The customer's heated part (subassembly) was made by placing a coiled tubular heater directly on the platen substrate. The heater was tack welded in place with wire, then potted in place with potting compound. The sub assembly was further assembled into a pedestal heater with a welded cover, shaft, sensor and water jacket. The resulting temperature uniformity at 700°C did not meet their performance goal of ± 5°C and the heater assembly process was complex and time consuming.

Solution

CAS proposed a form, fit and function replacement of the welded, potted heater subassembly with an IFC (Interference Fit Construction) heated part. IFC heated parts are ideal for applications requiring materials other than aluminum or exceeding the temperature capabilities of cast aluminum. CAS redesigned the heater element layout for optimized temperature uniformity and the IFC. The heater elements were precision formed and installed into the stainless steel substrate using the IFC method.

The resulting CAS solution was less complex and eliminated the need to weld and pot the element. Compared to the previous milled groove and potted design, IFC provided better heat transfer and consumed less total power. The intimate contact between the heater element and substrate delivered by the IFC method resulted in a higher performing and a more cost-effective solution for the customer.